The Superior Vena Cava
by and so they said always
Summary: After a heated argument (wherein neither can say "I love you", but both mean it), Castle decides that he and Beckett have an expiration date. But a killer's on the loose, one who specializes in ending the suffering of those harboring unrequited love. Soon, Beckett will be left with blood on her hands: she's always held Castle's heart, but soon that may extend beyond the metaphoric.
1. Chapter 1 - The Aphrodite Avenger

**Hi everyone,**

**So here's a brand new story for you all. I'm trying my hand at something with an actual semblance to a plot, rather than just relatively meaningless fluff (though this is still loaded with Caskett, don't worry).**

**ADDITIONAL PREMISE NOTES: this story is set in an alternate universe, wherein Beckett was never shot, Castle never said "I love you." (though he's still crazy in love with her) and Beckett and Josh have been broken up a while. Basically Season 4, but with a few signficant differences.**

* * *

**The Superior Vena Cava – chapter 1  
a caskett fanfiction**

There is a moment of silence, wherein both of them breathe for what feels like the first time in minutes. Finally, Castle breaks the quiet, and breaks a bit of her, too.

"We have an expiration date, don't we?" he concedes, a tone of sadness now mingling with the residual spite from their argument.

But anger still carves hard lines onto Beckett's face, her russet eyes burning with an autumn-coloured fire. In hours to come, she will regret not taking a breath at this moment, not taking a step back. But hindsight is of little use to us on Earth, and in the here and now, she speaks before the words run through her brain. "I guess you could say that, Castle, yeah," she hisses.

She sees something change in his face; it sets in most un-Castle-like way, simultaneously frustrated, empty and oddly vindicated, too.

As if he'd known all along they were headed down a dead end street.

Which they aren't, of course, Beckett assures herself. This is just one of their mid-case quarrels, wherein the mounting adrenaline and the constant, underlying tension between them unite to boil over. They usually fight for a few minutes about some insignificant detail or other, before someone interrupts them, and the topic and relevance of their conflict is forgotten within moments.

It happens around once a month. Never with Ryan or Esposito, just with Castle.

She supposes it's a side effect of working every day alongside with someone you're not allowed to want; not allowed to think you could love (and maybe already do).

This time is just like all those other times, right?

Except she's never seen that expression on him before.

It strikes more terror into her heart than a man with a gun. Suddenly the observation room in which they stand seems too small, the oxygen in here too little for the both of them.

"Then I guess there's no point delaying the inevitable," he says. He's not shouting anymore; he doesn't even sound mad. Just tired. Like he's run a really long marathon, only to find there's no ribbon and no crowd at the finish line. "Cut your losses, right, Kate? And move on. That's how it goes." Castle turns towards the door.

She has to ignore the slight irregularity in her heartbeat that accompanies his use of her first name, has to shut down thoughts like that.

"Hey!" Beckett storms after him, grabbing his upper arm and forcing him to turn back around and face her. "That's all I am? After more than three years of working together, I'm a loss to be cut?"

He frowns, and tilts his head, apparently in some kind of confusion. "No, not at all. _I'm _giving _you _a way out. Like I always do. It's pretty clear _you _need to cut some losses, Beckett. So, here we go." He grabs her wrist and tugs her away from him, much more gently than he could have. "See? Cut."

And then he walks out of the room.

Beckett glares after him. Breathes out. Takes a second to be still. She needs to think. Emotions are running too high at the moment. It's the fault of the case they're working on right now: an unknown serial killer is targeting those who bear unrequited love, cutting out their hearts and mailing them to the object of the victim's one-sided affections. It's messing with everyone's heads.

She nods once to herself, deciding to be the bigger one and apologise. She can't even _really _remember what they were fighting about. Well, on the surface. In reality, they are always arguing about the same thing. Their bickering can be translated as something like this:

Castle: "Dammit, Beckett, why didn't you wait for back up? The boys were only a minute behind us. He had a _gun, _for god sake! I know you see those every day, but you do realise they still have the power to _kill _you? Why'd you have to go straight at him?"  
(Which means something like _I love you, don't you dare do something that gives the universe a golden opportunity to take you away from me._)

Beckett: "Yeah, well, you weren't supposed to follow me! You're not a cop, Castle! I know you like to pretend you are, but you're not. Sometimes you just make it more dangerous for both of us when you do that tag-along to a takedown thing."  
(Basically, _I love you too, idiot, and if something happened to you, I'd never, ever manage to forgive myself. And I'd never want to._)

Castle: "Well, you _know _I'm going to follow! Wouldn't it just be better if we went in together at the beginning?"  
(Along the lines of _come on, Kate, can't you see that _everything _would be better by a thousand times if we were together?_)

Trying to look as collected as possible, and not at all like she and her partner just squabbled like schoolchildren, Beckett walks out of the observation room. Glances around.

She can't see Castle.

Esposito, clutching a few files, is making his way down the hall, humming a tune Beckett doesn't recognise.

"Hey! Javi. Have you seen Castle?" she calls out to him.

He nods. "Yeah. He just left. He looked pretty pissed, you know? Hey, are you two okay? Cos, you know, if Gates hears that y'all are fighting, she's going to want to shuffle things up. Then _I _might get landed with him," Espo jokes, before catching Beckett's expression, and realising things might not be so superficial as he originally suspected. "Seriously, though, Beckett. You're both okay, right?"

Beckett starts when she realises she doesn't know. This feels different. This feels bad. "Yeah, we're fine."

Esposito, looking satisfied with that response for the moment, nods and continues in his beeline for the case file storage: none of the killer's profiles he's found resembled the M.O of who Ryan had first deemed the Aphrodite Avenger, then the Eros Eradicator, then the Valentine Vigilante and then that was as far as he got before Esposito tried to shove paper in his mouth to shut off his stream of alliteration.

Beckett turns to stare at the bullpen, which is busy, yet oddly empty. His chair sits horribly unoccupied.

But he'll be back, won't he? Of course he will.

Tomorrow he'll walk through the elevator doors with two coffee cups, a cocky grin and an amusing story about Alexis, an idea for Nikki Heat, or just something generally ridiculous he thought of overnight.

Won't he?

* * *

_Five hours later…_

Beckett gazes blankly at her monitor screen, re-reading over and over the same line of a girl's statement about the bloody heart of her friend that she received, trapped inside a snow globe.

Someone taps her shoulder.

She jumps. "Oh. Ryan. Hi. What's up?"

The Irish detective twists his mouth in displeasure. "We got another one."

"Who got a heart this time?" Beckett asks, sickness coiling in her stomach. She used to think she'd get used to the horror and gore of this job, but the feelings have never gone away, not completely.

Kevin sighs. "It's not exactly like that. This time, all we've got is a giant pool of congealing blood, with a love heart drawn it. Like it was paint. According to Unis, it's pretty disgusting."

"I'll bet. Let's get going."

Ryan tilts his head. "You gonna call Castle? He'll want to see this."

"He went home. I don't think he was feeling well," Beckett lies neatly. She doesn't want to call Castle, because she's not sure she could deal with it if he doesn't show up.

"Oh. I'm going to give him a ring anyway," Kevin tells her. "Sick or not, this is right up his alley."

Beckett almost tells him not to, but it occurs to her that perhaps the writer will pick up for Ryan, even if he might not for her. That hurts a bit, too.

She tugs on her jacket, watching Kevin on the phone.

"Well, hello to you too, Castle's voice mail," Beckett catches him say. "Bro, just wanted to let you know that we've got another one for the Double A up in the alley behind the Split Quill bookstore. See you there."

Ryan turns back to her. "He didn't answer. Let's get going."

"You're calling our killer _Double A_?" she asks as they march towards the elevator.

Kevin nods happily. "Yep. For the _Aphrodite Avenger. _Cos, you know, Aphrodite was the Greek god for love, and these are cases when her grand Love plans aren't working out, and like -"

"All right, all right. We can call him Double A. I don't care. Just so long as we've got something to call him. I don't like nameless killers, it makes them seem omnipresent and powerful than they are," Beckett mutters.

She involuntarily turns to the empty space in the lift, expecting to see Castle there, offering a melodramatic comment about unknown foes.

But he's not there.

Beckett sighs softly to herself.

Maybe they had one argument too many. Maybe he couldn't take them, and their never being an 'us', anymore. Maybe he was right, and they had an expiration date: and they had reached it today.

But she refuses to believe it. They are Castle and Beckett, and they are always okay in the end.

Always.

* * *

Beckett wrinkles her noise slightly in disgust and shock at the sight before her. The dark red pools out across the chipped bitumen of the alley.

In the centre, carved with a stick into the setting fluid, is a large, roughly shaped love heart (as if it had been battered and beaten, over and over).

There is a zigzagging line cutting straight through the middle, declaring that this heart has been broken.

"Calling it – this is definitely Double A, extending his repertoire a little," Espo announces, while his fellows nod in agreement.

"Lanie, can you grab some samples? If the vic's in our system, we might be able to identify them through the database. If not, we're going to have a tough time getting a name without a body," Beckett notes.

Lanie frowns at the pool of blood. "I'm not sure if they're technically a victim yet, Beckett. Yes, this is a lot blood, but if it was a fully grown man, they might still be alive. Might. But I can't tell for certain, seeing as we don't know whether the owner of all this is a man or woman, or how big they were. I'll head back to the morgue and start analysing." She stands from her crouching position and heads back to the van.

When Lanie is out of sight, Beckett turns to the boys. "Does it bother either of you that Double A is changing his M.O, even if it's only a little bit?

Like he's sending us a message. Taunting us, you know? Like Lanie said, our guy might still be alive. It's like Double A is waving him in front of us, saying _here's someone you could save. Maybe._"

"Crazy-ass psycho," Espo says decisively, while Ryan nods fervently in agreement.

The entire time they are at the crime scene, part of Beckett expects Castle to respond to Kevin's call, or for the man himself to wander around the corner, and begin speculating beside her, like usual.

But he doesn't show.

* * *

_Two hours later…_

Beckett pushes open the double doors to Lanie's morgue. "Have you got an ID?"

Lanie nods. There's something in her expression Beckett can't quite comprehend. It's a complex mixture of disbelief and sickness.

"You know you can just call with that, right?" Beckett tells her. It's not that she doesn't appreciate getting away from the Precinct to talk to her friend, but today, after her fight with Castle, she doesn't feel like anyone asking her what's wrong.

"I couldn't call with this, sweetie," Lanie whispers.

Beckett tilts her head, suddenly catching onto her friend's demeanour fully. "Lanie… What is it? What's going on?"

Lanie takes a deep breath. "Good news first, or bad news?"

"…Good?"

"Well, I was right at the crime scene. The blood does belong to a full grown man, and there's a possibility that he survived."

Beckett half-smiles. "That's great, Lanie. If we send out a crew and work with some more profiling, we might be able catch this guy before he gets a seventh victim… oh. Right. What's the bad news?"

"The blood we found…" Lanie pauses for a moment, and then her whisper gets quieter still. "Kate, it belongs to Castle."

* * *

**Dun dun dun.**

**Hope you thought it was passable.**

**If this is the first fic of mine you've read, don't hesitate to go read any and all of my other ones. Please review/leave a comment, it really makes my day.**

**x. M**


	2. Chapter 2 - Blood On Your Hands

**Hi guys,**

**I was pretty surprised at the immediate response to this story - apparently you like the ones with plot.**

**Anyway, here's your next installment. I hope it all makes sense.**

**The mystery is much more complicated than it seems...**

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**The Superior Vena Cava ****– ****chapter 2  
****a caskett fanfiction**

Lanie knows it's going to happen before it does. She's seen it before, hundreds of times. She knows what to look for. The signs that Beckett is disappearing into her shell, pulling down the shutters.

"The blood we found…" she pauses briefly, wishing she could save her friend from the pain and burden of the knowledge that is about to crash down on her like a falling building. She lowers her voice, like it's a secret, like if she's quiet enough, she can tell Beckett without her best friend really having to know. "Kate, it belongs to Castle."

There it is. Lanie watches the spark go out behind Beckett's eyes, like a tiny candle's flame being doused by a tsunami. She sees the detective retreat back inside herself, to her own personal purgatory, like the vast expanse of a super nova folding back upon itself to form a dying star.

This is the place in her mind that Beckett goes to become Atlas: the zone of pain and detachment and alienation that allows her to hold the weight of the sky.

This is going to dig an endless, gaping rabbit hole for Kate, and Lanie knows right then that if Castle dies, Beckett will, in all essentials, die with him.

Beckett feels as if every one of her capillaries has been sucked into a black hole, leaving her staggering and empty. The blood in that street might as well be hers, seeing as her heart is pumping nothing but blank static around her veins.

White noise fills her ears, and Lanie suddenly seems very far away, as if the ME were a character in a show on a television screen, a programme Beckett is watching on mute.

She wonders if she'll be sick.

She doesn't think so. She lacks the energy to convulse. She's too hollow.

The edges of her vision begin to blacken, like the corners of a photograph curling away under the wrath of a fire. Beckett realises her breaths have become short and irregular, the kind in no way conducive to maintaining consciousness.

She puts effort into drawing in steady lungful's of air. In, out. In, out. In, out.

She hasn't felt this hopeless in a long time.

Her mouth has managed to reconnect to her brain, somehow, and has begun talking on automatic without her noticing. "Thank you, Lanie. I'll inform the boys. Keep me posted on any new developments."

Beckett's voice doesn't really sound like her own.

* * *

Castle wakes, feeling cold and sick, and not quite as if he is in his own body.

He's surrounded by several bleeping machines, and he's lying on a sterile-looking (and really profoundly uncomfortable) bed. A clear plastic tube penetrates the flesh of his arm, pumping a dark and suspiciously blood-like liquid into him from a bag hanging on a silver hook above his head.

It reminds him of being hospital, except the lack of any other patients, the absence of any windows, the shallow ceiling and the dull grey bricks all scream _someone's basement._

His heart suddenly stops.

Beckett? Where's Beckett? If he's in need of a blood transplant (he really hopes it's a transplant, and that he's not being poisoned with some weird substance), she must be in even worse shape than him, if she was with him when whatever happened went down.

_Was _she with him?

His memory is a little fuzzy, like a jumbled jigsaw puzzle...

They'd had a case. Yes.

_Over the past few days, three men and three women had received the still-bloodied heart of someone they'd known, preserved in a snow-globe. Some poking around had revealed the hearts belonged to a friend or acquaintance who had fallen in love with them (the new owners of the macabre snow-globes, that is), and whose feelings had either not been noticed, or not reciprocated._

_It had been a stressful couple of days for all of them. _

_When they'd worked out the serial killer's pattern (a psycho dubbed Double A by Ryan), the first thing Castle had done had been call Alexis, to make sure she didn't have any unresolved feelings for anyone at school. She'd gently reminded him that she was dating Ashley, and that while things were a little harder than they used to be, they were happily together. _

_In his head, he did a quick check on the team. Ryan was engaged to the love of his life; Double A wouldn't seek him or Jenny out. The only one Castle knew that Esposito had his eye on was Lanie, who, while reluctant to admit anything, was definitely as into Javi as he was her. _

_That left himself and Beckett._

_He was crazy in love with her, he knew that much. He was way past admitting it to himself, but not able to tell her, yet. And if Beckett isn't as over the moon about him as he is about her (it's actually scientifically impossible for someone to love a person more than he loves Beckett; he's got a few maths-y friends who could probably crunch the numbers and confirm that for him), that makes him a target. He's not too concerned, though. The killer doesn't really have a reason to seek him out._

_He'd worried about Beckett for a while. What if she was secretly head-over-heels for a guy she'd never mentioned? He hadn't thought so. _God_, he'd hoped not. _

Castle squints, trying to think past his pounding headache and recall what happened next.

He and Beckett had fought. He's pretty sure he'd started it.

Why?

_That's right. They'd been chatting to one of the survivors – a teenage girl (Angela, he thinks her name was), who was maybe only a little older than Alexis, and had been mailed the heart of Jason, the quiet boy who sat at the back of her maths class. Angela had cried, pondering how if she had known about the boy's feelings, things might have gone so differently. She'd never really known Jason, but she could have._

_And that, of course, had got him thinking about Beckett. Maybe if he just told her, something might change. If he told her that every time his mobile rang he silently prayed it was her, how each time she smiled he felt like he could run a mile, and that he cannot stop replaying their one and only kiss in his mind on loop._

_This thought had brought that night in the alley to the very forefront of his mind (not that it was ever that far away), which turned out to be a rather bad idea. Because all he could think about, then, was kissing her again. Longer, harder and for real. _

_And, somehow, just his thoughts have a way of upping the ever-present electric tension between them. So, eventually, the energy connecting Castle and Beckett had blown up. And because it could never end with him pushing her up against the wall and kissing her senseless, it exploded into a loud argument._

Oh. Expiration dates. Right. That's what he'd said.

He hadn't meant it.

He would've come back the next morning (who is he kidding, he'd have been back within the hour), but… _something_… happened.

What?

It must have been something big, to be able to keep him away from Beckett and land him in some kind of dodgy looking medical room.

Castle starts as he hears the shuffling sound of approaching feet.

He glances around, and catches sight of Lanie's ME friend, whose lab is across the corridor from hers. He's always smiled at Castle and Beckett when he catches sight of them in the hallway. He's a handsome enough chap, with thick blond hair and dark grey eyes, maybe sneaking up on thirty-eight.

"Oh, Mike," Castle breathes. "Hi. Am I at the Precinct? Why am I down here?"

Mike smiles patiently at him, tossing a round object from hand to hand. "You lost a little blood. I'm just fixing you up. But we're not at the Precinct, Mr Castle. Nor at the coroner's facility. We're in my own little lab."

"Why?" Castle asks, confused.

Mike gives a little shrug of his shoulders, as if he sympathises with Rick's confusion. "I need you, Mr Castle. For now, at least. You're one of the steps to my end game, you know? One of seven little steps, actually. You're the last."

That's when Castle realises that the ball that Mike is tossing back and forth through the air is not a ball at all, but a snow-globe. "Mike…" he trails off, not wanting to get on board his current train of thought, the train that is screaming that the timid, polite and friendly Mike is a serial killer.

Mike waves his hands hurriedly to dissipate Castle's concerns. "Don't worry, Mr Castle, I'm not a psycho killer." He laughs a little self-deprecatingly, and Castle almost breathes out. "No. I'm just a man with a plan. And, like with an autopsy, there are steps I have to follow to achieve the perfect outcome, the perfect result."

Castle's not sure he wants to know the answer, but - "Mike? What's your… 'endgame', exactly?"

Mike smiles happily, wistfully. "Kate Beckett. The detective. God, I love her so much. She's so beautiful and clever and broken and perfect. But you know that, don't you? And she's so much better than the likes of you and me – she'll just fly right you by unless you manage to flag her down. You got her attention by muscling your way to her side, pulling all the strings just to annoy her. I'm going to _interest _her, Castle. I'm giving her a case she'll be desperate to solve. Heart-wrenching and fascinating at the same time. You had to drag her to you, but she'll _come _to me. I've given her a trail of bread crumbs, a trail of hearts, that she'll follow, and it will lead her back to me. All those years of watching her walk down the corridor to visit Lanie, only being able to give her a smile. But I want to give her everything. I took you, Mr Castle, and wrapped your disappearance in just enough intrigue to ensure that she'd follow you anywhere. She'll find us here, eventually. And we'll be able to meet, really and properly." Mike looks incredibly excited, and Castle feels incredibly sick. "At first, I'll have to keep her here, of course. A little bit of force, that's all. But then she'll fall in love with me, just like I've been in love with her, all these years. And then we'll run away together. But don't worry, Mr Castle. As soon as Beckett arrives, I'll let you go. A life for a life, you know? The minute she's safe and secure, I'll escort you back to the city."

"I'll just come right back. I'll always come back for her!" He tries to sit up, but he's strapped to the bed.

Mike smiles again, sadly, with pity for Castle mixed in. "I'm a doctor, my friend. I have a few tricks up my sleeve to ensure you don't remember our location until we're long, long gone. Goodbye for now, Mr Castle. I'm off to go to the Precinct, to offer Beckett a _very _important clue to your whereabouts that Lanie _must _have somehow missed." He tuts disapprovingly. "What a shame. Don't worry, Mr Castle. I'll make sure the clue's a good one, the kind that will lead her here, blinded by curiosity and adrenaline. It'll be tantalising enough to ensure she comes immediately, and lulling enough to mean she comes to scope it out alone. And _then, _Mr Castle – well, you'll be free to go."

Mike gives him a little wave, and then departs, retreating into the darkness. Castle hears a door open and close.

He wants to throw up.

Mike, a familiar face, committed _six _murders to build a trap for Beckett, to wave in front of her like a shiny toy. And to make the cherry on top, he took Castle, too; the subtotal of these circumstances is the perfect bait for the perfect detective. The profilers on the Double A case had said that the killer was likely the victim of unrequited love himself. Except Mike doesn't _really _believe it's totally unreciprocated: he seems to think that all it will take is proximity and a little careful prodding before Beckett will fall right into his arms.

That once he's captured Beckett, she'll learn to appreciate the little puzzle he built for her. The puzzle of murder and heartbreak and loss and suffering, all sewn together with neat little clues.

And Mike is going to go find Beckett right now, and hand her information that will lead her straight to him, Castle, and ultimately her ensnarement.

* * *

Beckett has reached a dead end, and the bile is rising in her throat. She cards a hand through her hair, leaning heavily on her desk.

There are no clues, no traces, no viable suspects. Nothing to lead them to Castle, and it's closing in on eleven. She's sent the boys home, she wants them working at their best tomorrow, and it's not looking like they'll get a break anytime soon.

There must be something she's missing, some vital factor that they've all overlooked.

She's been over all the interviews and statements ten times at least. Perhaps Lanie has something new? She needs something, or she's going to break. How, she doesn't know. But Beckett is close to fracturing and shattering apart.

She jumps up from her desk, grabs her leather jacket and ducks into the elevator, intent on reaching the ME's lab.

Beckett stares at the way the invasively bright light reflects off the sterile white floor of the corridor. She's so fixated that she doesn't notice the approaching person until it's too late, and promptly walks straight into them.

Beckett lets out a small noise of surprise and stumbles back slightly (her cat-like reflexes dissipate after thirty-five hours without sleep), but strong hands grab her shoulders and steady her.

She looks up into what is thankfully a relatively familiar face: Mike, the sweet, quiet, friendly ME who works across the hall from Lanie.

"Detective Beckett! Hi. I'm so sorry about your friend Castle," he murmurs, concern in his eyes. He's still holding her tentatively.

"Mike, I'm sorry, but I really don't think I can talk about it right now -" she begins, but he interrupts her.

"No, I was just coming to find you. See, I know you and he are partners, and I figured you'd probably be taking it pretty hard. The police force can't lose one of their own, even if Castle's not really a cop. Anyway, I offered to look over the case file, in case Lanie missed something. An objective eye, you know? A fresh start."

Beckett takes a breath. "Oh. Thanks, Mike. So much. For trying."

"Not trying, Beckett." He gives her a bright grin. "Succeeding. Come on. I found something for you. Something important. I'm no detective, but I reckon it'll lead you straight to Castle, and whoever it was that took him."

* * *

**Dun... dun... dun... MYSTERY**

**I figure I'm doing all right with my first fic with an actual plot. **

**Please leave a review, they make my day. I've also released some new stories since I last updated this one, so if you're feeling Casketty, feel free to go check 'em out.**

**x. M**


	3. Chapter 3 - Below

**Hi guys,**

**Wow. Thanks for your response to this story, it's becoming more popular than I originally expected. **

**I hope you enjoy this chapter, and be sure to message me if something doesn't make sense.**

* * *

**The Superior Vena Cava ****– ****chapter 3  
****a caskett fanfiction**

_She's so still._

_Her head rests in his lap, and he brushes his thumbs over her pale cheeks desperately, trying to ignore the fear spreading through him faster than the blood spreads from her._

_Castle's breathing fast, perhaps to make up for the fact that she's barely breathing at all. _

_"Kate… Kate… Come on, Kate. Come on," he murmurs gently, trying to call her back. But it's no use: she's in an unreachable place, like when she's in the middle of riddling a complex clue. _

_Mike is crouched next to him, and despite how repulsed Castle is by his very presence, he's so focused on holding Beckett that he won't even try to raise a hand to push the killer away. _

_"I didn't do anything," the man is chanting. "I didn't touch her. The beam fell. The beam above her. This is an old building. I didn't do anything."_

_"Well, do something now!" Castle snaps back, blocking out the blood coating his fingers. _

_"I work with the dead, Mr Castle, not the living!"_

_"Well, leave it much longer, and she'll be right up your alley!"_

* * *

_Three hours earlier…_

Mike had found the barest suggestion of a boot print at the edge of the pool of blood in the street (it helps her not to think of it as Castle's).

He'd gone through the samples and amassed the particulates left by the wearer of the shoe; he'd then sent this information to a friend at a nearby university, who'd run the data through his Mass Spectrometer.

The results had come through, and now are sitting on Beckett's desk under a blaring light. Mike hovers at her shoulder, quickly explaining what all the figures and diagrams mean.

"And, as you can see from this Venn Diagram, there is only one area in which all three of these types of particulates can be found… I won't bore you with the science, Beckett, but your best shot of finding him would be here." Mike taps his finger at a block in the darker, dodgier area of the city.

"Are you _sure_, Mike? I don't have time to be chasing dead ends," Beckett reminds him, doing her best not to snap.

"Detective Beckett, I'm positive," he assures her. There's something odd in his tone of voice, but she doesn't bother to decipher it. Because suddenly she's one step closer to Castle and that's the only thought in her head that's worthy of her attention.

"Okay, listen, Mike, I'm going to call in the boys. Thanks so much."

But Mike's shaking his head. "Just get there as fast as you can, Beckett. They might not still even be there, if they're there at all. Trails like this go cold faster than you'd believe. You get going now, I'll call the boys and send them over to you," he promises.

"All right. Thanks. Bye." Beckett grabs her jacket and tugs it on, even as she's running to the elevator, slamming her hand on the button for the ground floor. "Come on, come _on,_" she breathes in frustration.

Beckett has no way of knowing that in just a few hours, Castle will be echoing those very same words.

* * *

Castle wakes with a jolt.

"Don't panic, Mr Castle, it's just me. I'm detaching you from your monitors – you're all better now. I really must apologise for having to borrow a bit for your blood there, my friend. It was just to get the ball rolling. You understand?"

Mike is leaning over him, talking calmly. Castle desperately wants to punch his stupid lights out before he can lay a finger on Beckett, but straps still hold his arms, legs and torso tightly to the bed.

Mike smiles softly at him. "I'm just going to have to calm you down a bit, so I can move you to a less obvious location."

Castle feels the needle pierce his arm, and there is absolutely nothing he can do about it. Nothing he can do about anything. Suddenly, he becomes nothing but a dead weight, though his vision remains painfully clear, as do his thoughts.

He is aware that Mike is removing his restraints, and he attempts to lash out. His body has committed mutiny, however, and he remains resolutely unmoving, much to his intense frustration.

Castle is eased into a wheel chair, and down a shallow ramp to a small room, maybe five metres by five metres. A sub-basement, perhaps? A very long way from fresh air and light and freedom, at least.

He makes a last-ditch effort to overpower Mike, though he knows by now that it's totally in vain; as he anticipated, he remains still.

Mike tips him none to gently onto the cold, hard stone floor of the room, and he lands loudly.

"Oh, before I forget, Mr Castle. I've given Detective Beckett the last piece of the puzzle, the key to it all that will lead her to you. Well, to me. Your part to play is almost over. I must thank you for your cooperation."

The ME sounds so genuine that Castle feels sick. He watches hopelessly as the younger man leaves, heading up to a higher level of the building, presumably to wait for Beckett's arrival.

Castle prays and prays to whatever ethereal and powerful supernatural entities that exist that Beckett ignores the clue. Gives up on him.

But she won't, she never will, and he _knows _it.

Because he's Castle, and she's Beckett, and they most certainly _do not _have an expiration date, not ever, not if he has anything to stay about it.

* * *

She's searched six buildings.

The boys should be here by now, to speed up the search. Where are they? They're almost as anxious to find Castle as she is. They would have driven to her at top speed, sirens blaring.

Come to think of it, she never did see Mike pick up the phone. She shakes her head to clear the doubt in her mind. Why wouldn't he call for her backup, after he'd promised? After all, he was the one practically handing her Castle's location. But she'd been running and distracted when she left the Precinct. He had probably dialled Esposito and Ryan straight after she'd left.

Beckett nearly screams in frustration when she vacates the seventh empty building in the area. She's been at this for over an hour and a half.

Mike had said trails like this go cold fast.

She can't let this one go cold.

She can't let Alexis lose her father, Martha lose her son. And _she_ can't lose him… whatever he is… whatever they are.

_Were, _a voice in her mind whispers. _Remember? The last thing you ever did was fight._

Well, there is no way in heaven or hell that Beckett is going that argument be the final moment they share.

No.

This next building looks promising – old, unstable, abandoned and decrepit. She's been in a few designed just like it for previous cases. They're the sort with deep basements, sometimes more than one. The perfect place to hide a hostage.

Or keep a body.

Pushing those thoughts to the back of her mind, Beckett tries the front door.

It's unlocked.

Either Double A is sloppy, confident, or in another place entirely.

She edges into the lobby of the crumbling statement of wood and stone – rotting beams of timber line the ceiling, and columns rise to meet them from the floor. Beckett holds her gun in both hands, steady and precise and ready to fire at any moment.

Carefully, she advances, side-stepping junk and old furniture as she goes. She wants to turn on her torch to better guide her path, but if the killer is, in fact, lurking here, that would be like yelling, _"I'm here, come shoot me!"_

Beckett works her way from one room to another, scanning them for any trace, any hint, any lead. She's so focussed (and tired and scared about Castle and not at all on her A game) on the search that she doesn't notice the footsteps behind her, not until the other person is close enough for their breathing to be audible to.

Beckett whirls around, her back thudding into one of the support columns. She feels it give a little (that's not good), but she's too busy watching the figure approaching her through the darkness.

"NYPD, get down on your knees!" she orders. The intruder is undeterred, and continues his path towards her. She opens her mouth to shout at him again.

But then there is a loud groaning, snapping noise from above as one of the thick, rotten planks works itself free.

Then Beckett feels as if she's been hit in the back of the head with an axe, and whatever light that is left in her world goes out.

* * *

Castle's regained almost full control of his body when the door to his makeshift prison opens again.

Mike staggers in, a small, lithe figure thrown haphazardly over his shoulder.

Castle would recognise that form anywhere – he's spend over three years 'observing' her, and at least two years loving her.

"That's Beckett! Mike, what did you do to Beckett? Mike!"

Mike stumbles. Apparently, ME's don't have to lift much heavier than a test tube, because Castle knows for a fact that Beckett is really very light.

Castle darts forward in less than an instant, relieving the horrid man of his incredibly precious load. Beckett is limp in his arms as he holds her in a hollow mocking of the bridal style. He sinks back to the floor, supporting her carefully, checking her desperately for the cause of her terrifying stillness.

He finds a huge, bloodied mark on the back of her skull. Blunt force trauma – he's used to seeing it on the bodies they deal with. He _cannot _see it on her.

He lays her out on the floor, focussed on shielding and examining her head.

She hasn't even stirred off her own accord; her breathing is barely there. Her pulse is that of a fading butterfly's wings.

No, no, no.

"Kate… Kate… Come on, Kate. Come on," he pleads with her. Surely she must know he needs her back with him, here, now? He has to tell her he never meant what he said about expiration dates, that he'll stay by his _always. _

But now he's holding her and she's not there. Not really.

Now Mike is explaining about how he followed Beckett into the house, tailing her as she chased the clue he'd dangled in front of her. How she'd seen him, turned to face him. Then the ceiling beam had fallen, and knocked her to the ground. He'd thought she'd get back up, Mike told him desperately, but she'd stayed there. Unmoving. Unresponsive.

Dead to all the world.

The blood is sticky in Beckett's hair, seeping out of that very scary head wound. She's not bleeding out – there's not enough for that. But he knows injuries like this are some of the most dangerous of them all. Brain damage, haemorrhaging, comas and…

And Mike, the only one out of the two of them with any idea about medicine, is completely useless

"I work with the dead, Mr Castle, not the living!"

"Well, leave it much longer, and she'll be right up your alley!" Castle lets the words escape, voicing the fear that is now curling like smoke in his mind. "How come you could pump me back full of blood, but you can't fix her?"

Mike wrings his hands. "I had _planned _what I did to you. I cut you in just the right places, and healed you exactly right. I have an extensive knowledge of anatomy – I have to. But brains, and heads and minds… they are not something I know about. When you are trained to be a coroner, they don't spend a lot of time teaching you to keep someone alive!"

"We have to take her to a hospital," Castle almost yells. "Don't you love her, too? Don't you want her to be okay? We have to take her to a hospital."

Mike wavers, clearly indecisive, and just for a second, Castle thinks he's convinced. But – "No, Mr Castle. I've waited too long to have Kate as close as she is now. We're just about to start our time together. I can't risk people, police or hospital staff, who don't understand our love, trying to take her away from me," he explains.

"You don't get to call her Kate!" Castle spits in reply. You have to earn that with Beckett. You have to get her to trust you enough to let you through the front line of her walls. "And she's not in love with you!"

Mike sighs. "You're in love with her, too. I don't blame you, and I won't punish you. If anyone can understand your predicament, it's me. But you're deluded, my dear fellow. Your love is one sided. She wants me. Only me. And she and I, we have to stay together. No hospitals. No anything. I'm just going to get some fresh bandages, and some things for her. Stay here and watch her, Mr Castle. Take care of her for me. When I return, rest assured, the first thing I will do is to escort you home, unharmed."

And before Castle can respond, before his brain can connect with his mouth enough to say anything at all, Mike had stood up and left the room, muttering a list of things he must acquire as he goes.

Castle hears the thick chink and slide of three heavy dead bolts, and the bleeping noise of something that could be a monitor, or a trap. He doesn't know. Not that he'd try to escape with Kate like this.

She looks so small, so beautiful and oddly peaceful.

And so very, very still.

* * *

**Please review/comment/PM, they really make my day.**

**I hope you're still enjoying the story, and feel free to leave a guess in the reviews as to where the story is going, or where you want it to go.**

**A/N: Note, I haven't really mentioned Alexis. This is mostly because I don't think I could write her very well. Anyway, she will be appearing later, I just didn't want to have her all angry at Beckett for getting Castle into trouble; I much prefer it when they're all happy family etc.**

**x. M**


	4. Chapter 4 - Best For the Both of Us

**Hello, everyone!  
Apologies for the massive hiatus. I haven't had a computer or internet for a while, and I only just got it back. Plus, I've had a ton of exams. Many sorries. **

**Anyway, I return with many new ideas.**

**Hopefully you'll keep reading and enjoying this story. It's my only actual crime story for a crime show, which is amusing**

* * *

**The Superior Vena Cava ****– ****chapter 4  
****a caskett fanfiction**

Castle just stares at her for another few moments, as if through sheer force of will he can bring her back to him. As if somehow loving her is enough to make her open her eyes.

But it's not.

She _has _to be okay. He's not ready to say goodbye to her yet. Truth be told, he'll never be ready. He's wanted forever with Kate Beckett for a long, long time, and now he suddenly has to stare down the barrel of forever _without_ her.

He'd have to go back to that life he used to love, which he never noticed was plastic and boring until that day she stood in front of him and raised her eyebrows, slamming the world into vibrant and exciting technicolour in half a heartbeat.

He sighs at the memory, a tiny smile tugging the corner of his mouth. While Beckett maintains it was entirely coincidence that their paths ever crossed, he remains one hundred percent sure it was fate.

But he doesn't want to think about fates, because Beckett is a tragic hero, and everyone who has ever read a story knows exactly what happens to tragic heroes when fate steps in. The dice gets rolled, the cookie crumbles, the cards are dealt. And the tragic hero dies.

Every time.

Suddenly his breathing is as shallow as Beckett's. He lifts her up onto her lap, cradling her as close and as gently as possible.

Her head tucked into his shoulder, he continues to whisper to her, hoping vainly he's reaching some level of her subconscious. Maybe he'll be able to coax her out of the darkness, hold her hand tight enough to pull her out into the light.

"Hey, Kate. Hey, beautiful." He can call her that, because she can't hear him. He wishes he was allowed to tell her things like that every day. He wishes it wasn't always life and death that brings them close.

He feels her shift slightly in his arms, and he freezes. Her hand fists in his shirt, tightly, just for a moment, before she relaxes and goes horribly limp again.

After a moment, Castle realises how cold she is. Keeping her steady, he shrugs off his coat (it's his favourite jacket, and she's his favourite anything, so he supposes they go well together) and wraps it around her, trying to warm her up a little more.

He doesn't know how long they sit like that, he painfully awake, she painfully asleep, both waiting for some kind of absolution: death or salvation.

Castle, so caught up in Kate, starts when the door clicks back open and Mike shuffles in, several duffel bags hung from his shoulders and gripped in his hands.

"Here," Mike tells him confidently. "I've got everything to two of us will need. Don't worry yourself, Mr Castle. Kate will be fine, in time. We'll get to live happily ever after. Don't you think that is what she deserves, after everything, after everything she's lost?"

Castle would slam that rat up against the cold cellar wall if he wasn't too preoccupied with the far more important duty of harbouring the precious person in his arms. "She _does _deserve a happy ending, more than anyone. But you can't force her into it. She has to want to, Mike."

He deliberately doesn't count all the minutes and moments and years he's spent hoping she would come to him. How close they manage to get to each other, time after time, but never quite there close enough.

Mike glares at him. "She _does_ want me, Castle. More than anything. She wants us. She just doesn't know it, yet. But she'll learn."

Castle opens his mouth to say something – he doesn't know what – when Kate wriggles again, just a little.

"Kate?" he asks, trying to call her back to him.

"Hey," He hears her breathe so quietly it's barely audible.

Castle wants desperately to tell her that everything is all right. That they'll both be fine, be warm and safe real soon.

But he doesn't lie to Kate Beckett (except for that one, terrible lie by omission: he hasn't told her he's desperately, completely, down-the-rabbit-hole in love with her).

"What's going on, Castle? What's happening? Are you okay?" Beckett's voice is as hushed as a sparrow's wings, like talking is a painful burden that she must carry anyway.

Castle almost laughs at her. "Am _I _okay? I'm fine, Kate. I'm great. Are you okay?"

She sighs. "I'm alive." She sounds almost cross – clearly the whole unconscious thing has been a great inconvenience for her.

He adjusts her in his arms so that he can gaze at her face. Beckett's eyes are still half-closed, but he can see a flicker of the old fire in their hazel depths.

"Enough talking," Mike interrupts. "We have a schedule to keep. Even in New York, it is impossible to stay hidden forever."

Beckett tilts her head to isolate the speaker, the tense pain flickering across her face briefly at the movement, before she quells it. Confusion knits her eyebrows when she registers the presence of Mike.

"Mike? Why are you here? Did you follow me? What's going on? Castle. Mike. Tell me what is going on," she demands.

Castle knows the knock on her head must have been pretty bad for her to not have put it together yet. Either that, or she's in some kind of denial.

Mike's uncontrollable excitement bubbles over. "We're running away together, Kate! You and me."

More puzzlement. When she speaks, her voice is oddly plaintive, like a child. That, and the fact she hasn't leapt out of his arms alerts Castle that she may not be as lucid as she seems. "But I don't want to run away together. I want to go back to the Precinct."

That, Castle supposes, is the Beckett Equivalent of _I want to go home. _

"No, you don't. You're just confused right now because you had an accident, and you hit your head," Mike explains. "But you'll understand later. And don't you worry about Castle, here. He's headed home very soon."

Castle shakes his head violently. "Take her, take me too. You can't just abandon her somewhere when she's like this. I know she's strong and impossible and can do bloody well anything, but you can't let her run herself into the ground. Let me come with you, Mike."

Again, Mike hesitates. Castle thinks he's got him.

And, perhaps, though he'll never really know for sure, Mike nearly did agree. Maybe everything could have turned out drastically different if the ME had caved in that second. In another life, tragic endings could be averted, love could be found, and they could be safe.

"No, Mr Castle. You might try to take her away from me. And I can't have that. I'm sorry. I really, genuinely, am. But while it's hard right now, you'll understand some day. Just like Kate will."

Castle reckons he's got one good shot at getting them out. If he can gently set Kate down, he can probably overpower Mike, even if he's still a little slow and groggy from the various drugs that have been pumped into him.

The ME seems to know what he intends, however. "Touch me, Castle, and Kate will die."

"You haven't got a gun. You haven't got anything." Castle's growing in confidence.

"I don't need a gun, you idiot. I'm a doctor. You really didn't think I'd do all this without some kind of insurance policy, do you? I wasn't born two hours ago. If you look carefully, you'll find a small needle mark in Kate's arm. I've injected her with a small amount of a lethal, slow acting poison named _Faramoxynderilide_. It's my own special concoction. You lay a hand on me, and you'll never find an antidote in time. All the medical experts in the city couldn't pull it off fast enough. She'd be dead in a matter of hours. So you let me take Kate, you let me go, and I'll cure her and make sure she lives a long life."

Castle's heart stops.

Beckett finally speaks again. "Are you going to let him go home safe?" she asks. She's talking to Mike, not to him. "Is he going to be okay if I agree to go with you?"

Mike nods vigorously. "Of course. He'll be just as healthy as the day before he met you."

The last day before his life became the best thing ever. Back to a world that is black and white without Kate Beckett to set it aflame.

Without his curious, frustrating, fascinating, beautiful, irritating, unfathomable, _perfect _Detective.

Well, Castle thinks, he's never, _ever _going back to a world like that.

But before he can tell them both that, Beckett's talking again.

"Okay. Okay."

Kate moves in Castle's arms, as if to stand up, but he won't let her go. "What? No! Kate, you don't get to decide."

"And you do?" she snaps back, but he can tell the faked anger is just a smoke screen. She's worked out what's going on now, and she wants him to leave before it all falls apart. "This is my life, Castle. And I'm allowed to put a higher value on your survival than mine, if I want."

"No, you -"

"I'm a cop, Castle. If something like this doesn't happen today, it'll happen tomorrow. People in jobs like mine have predetermined expiry dates, Castle, and you know that. But you can go home, and stay safe for a good, long time," she explains, her tone a mixture of sadness, wryness, defeat and a touch of ordinary, challenging Beckett.

He flinches at the phrase _expiry date. _His words from before accidentally thrown back in his face. How he wishes he could take them back, and just tell her what he really wanted to say: _I love you. _

"I'll be fine, Castle. And you will be, too," Beckett whispers in a softer, kinder tone.

(He'll never be fine.)

He refuses to believe she's just going to hand herself over to a crazed, obsessive serial killer. Maybe she's got a plan?

But Beckett is starkly rational. She's virtually incapacitated, with a dangerous head wound. He's fighting off the sluggish lasting effects of Mike's drugs. She's been poisoned. They're both lost and weak and injured. The ball is in Mike's court, and all the cards are in his horrible murderer hands.

So, logically, she's arrived at the only conclusion she can. Do something to keep at least one of them safe.

Him.

Mike sets down the duffel bags, and reaches for the collapsible wheel chair he'd abandoned in the corner. He deftly sets up, ready for her. To get into, and be taken away for god knows how long.

Suddenly, Mike is just inches away, and something sharp is jabbing the back of Castle's neck. He reaches to fend it off, but darkness is already muscling into his line of vision.

And then Beckett is being lifted up, out of his arms, and she's not trying to come back to him.

Of course she's not.

She thinks this is best for everyone, best for him.

His eyes are starting to close off their own accord, and there is nothing he can do to stop them, just like there's nothing he can do to stop her signing her life away to protect him.

Castle's not sure, because his vision has become blurry, but it looks to him as if Beckett's got a sad little smile on the corner of her mouth and a searching look in her eyes, like she's trying to make sure she has one last memory of him.

* * *

**I know it's a little short, but I hope you thought it was interesting nonetheless. I'll be updating other stories soon.  
Once again, all reviews/comments/complaints are appreciated, and check out my other stories if you're feeling unbearably bored :)**

**x. M**

* * *

**Sorry, just a couple more things. **

**1) why are my documents disappearing in the Doc Manager thing? Chapters I wrote earlier this year have vanished and I don't know why, cos I didn't delete them.**  
**2) do I have any male readers? For some reason I just feel like everyone who read my work is a girl (that's NOT me being sexist - I am a girl), because a lot of reviews mention being girls in their reviews. So I was just wondering if there are any guys out there reading?**


	5. Chapter 5 - Safe and Bound

**Hi everyone**

**Apologies for the incredibly long hiatus. I'm a terrible person. If it's any consolation, it's because I finally found a way to download the Nikki Heat books, and have been reading about one a day, and I'm also rewatching Castle for the big return.**

**Hope you enjoy as the plot thickens...**

* * *

**The Superior Vena Cava ****–**** chapter 5  
****a caskett fanfiction**

She recognises the expression on Castle's face as she waves goodbye.

Heartbreak and Kate Beckett are no strangers to each other; some might even call them old friends.

Her life has been a patchwork of goodbyes: her mother, her mentor, her captain. She knows the hollow eyes, the airless lungs, the confusion, the desperation and the loss like the back of her hand.

Things she has now written all over Castle in a bold, burning, ever-lasting font.

Every inch of him cries that he is saying farewell to someone he loves.

And, oh, how she hopes he is familiar with the signs that are radiating from him now, just so he knows, so he understands: so he can see that the same pain, the same ache, the same echoing lament is washing her clean, too.

Then his eyes flicker close and he stills, the frown clinging to him, his hands still fists at his sides.

She's going to miss him more than anything. She's going to spend forever imagining bitter-sweet what-ifs in which they swallowed their pride years ago, gave into the repressed feelings and quit wasting time.

If they'd had a few months together, years even, then perhaps she wouldn't feel so lost. As if fate has cheated her out of what could've been the best thing to ever happen to her. Although, she supposes, getting any time with him at all was a small miracle.

Leaving now with Mike, clad in the memory of him looking at her like she'd just tugged the tablecloth out from under his world, Beckett thinks that this hurts her heart more than any bullet, knife or poison ever could.

In less than five minutes, Beckett is securely fastened into the back seat of a nondescript van – the kind soccer moms use to cart their kids around. The kind that screams, _these are not the droids you're looking for. _It's inconspicuous, the very sort of car she herself would choose if she didn't want to get pulled over. It's even got _Support Obama _and _My Family _bumper stickers. She'd be impressed he didn't choose a looming SUV if she weren't worrying about her diminishing chances of a lucky escape._  
_

"Can't I ride shotgun?" Beckett pleads, doing her best to sound innocent and childish. Hopefully, Mike won't guess her ulterior motive: she can lean as close as possible to the windshield, and hopefully traffic cams will pick up her face when they put an APB out on her and her captor.

"No. I can't take the risk that you'll be seen, and we'll be apprehended. The others, Kate, they don't understand how we feel about each other. I can't take the chance they'll stop us now, not when we're so close to the happily ever after we've always dreamed of."

Beckett's about to snap at him that she's only ever dreamed of one happily ever after, and it was with the man they've just left behind. But then the case they worked with Jordan Shaw pops into Beckett's head like a soap bubble bursting. How the FBI agent had profiled the killer as one with an illusion involving a relationship with Detective Nikki Heat, and how once the hallucination fell apart, he had become more violent and dangerous.

Perhaps she ought to play along. With the thundering wound on her head (she can still feel the stickiness of the blood, the same way she can still feel the warmth of Castle's fingers) and her general shock and disorientation, not to mention how her service piece is now at Mike's hip, not hers, she's not really in any position to fight.

"Of course, Michael," she murmurs, going for a custom blend of agreeable, obedient and excited. "We're so close to everything we've ever wanted; it would just break my heart for things to go bad now."

(Too late: her heart's already broken. It broke when they left that room without him.)

Mike looks delighted that she's finally seeing sense. "See, beautiful? I knew you'd understand. Love is a battle you have to keep fighting until you win. If it's worth it, if it's the real thing, everything works out in the end."

Maybe in the stories, Beckett thinks. Not for her.

Mike climbs into the driver's seat. "Okay, we're going to have to just drive for a little bit, just to get out of the zone, but then we can pull over and get you something to eat, okay?"

"Where are we going?" Beckett tries. She's not sure what she'd do with the information if she got it, because she's fairly certain Mike has taken her phone, as well, and if he's smart, turned it off and taken out the batteries.

Mike shakes his head. "It's my little surprise for you, honey. You'll love it."

A small, pathetic excuse for a half plan wriggles to the forefront of her mind. "I won't love it if I have to wear these same clothes over and over. Can we go by my apartment so I can get some things?"

Another _no. _"No need, Kate. I've got plenty of clothes for you at our new home, and some of your things. I can go back for anything else if you want later, when the inevitable hype has died down and it's safe for me to go back to your place."

"You've really thought of everything, haven't you?"

Mike mistakes her tone for one of pride, not hopelessness and horror, and he nods happily. "Yes, Kate. There's no reason for us to ever, ever be apart again."

* * *

Someone's shaking his shoulder, rousing him from the veritably infinite twilight space of sleep.

He doesn't want to wake.

In his dream, he's sitting with Beckett on his couch. She's nestled into his chest, and his arms hold her comfortable and close. They're not doing anything in particular. She's reading one of his manuscripts for the new Nikki Heat book, adopting a sarcastic air whenever she encounters some of his more imaginative and fanciful imagery, laughing at him quietly. They're not kissing or discussing the future or fighting or anything. They're just _being_ together and it's the best dream he's ever had.

And now some intruder his shattered his temporary, slumber-induced bliss.

Groggily, he opens his eyes to the shining grey eyes belong to someone who not only stole his dream just then, but also took the possibility of it ever being a reality.

"Hey, Mr Castle. Time to wake up. You're going home, my friend. You've done an excellent job, and played your role perfectly. I really do owe you one."

"We're Beckett? Where is she?" he demands, his voice lacquered in sleep.

"She's at the first safe house. Once I've taken her home, we'll keep moving."

"How long have I been asleep?"

"I knocked you out when she and I left… so… I'd say just shy of sixteen hours."

Castle does a quick calculation. That means it's approximately eight hours to wherever Kate is being held captive. "So you're taking me home? That's it? Why don't you just kill me?

Mike looks a little hurt. "I'm not a bad man, Mr Castle, and I have no quarrel with you. I needed you as bait, and now I need you to let it lie. Move on. Let go. We were both fighting Love's Battle, and it looks like I won. Me. Beckett's mine."

"Beckett doesn't belong to anyone. You're just incredibly lucky if she decides to let you be a part of her life."

Mike smirks, sounding smug. "Maybe that's as far as you've got, but you were never as good as me. Kate Beckett and I are soul mates, and I assure you, she _is _mine, and _always _will be."

The use of the word _always _jars Castle. That's _their _word. His and Beckett's.

He'd meant it when he told her that. Promised to be there for her, forever. He just hopes she knows. He hopes she can see past that the last moments they ever really spent together were fighting, and understand that he'll always love her, and never stop looking.

His life was dropped on its head that day at the book launch, and now, everything has been upturned again. The arrival and departure of Beckett.

Mike's talking again. "Now, you and I, we're going to go back to the Precinct together. I'm going to be the hero who discovered you, and you're going to play along. Beckett said she was busy, and neither of us know where she is, got it? Then, I'm going to resign my job as an ME, because unfortunately, my mother in South Carolina has been diagnosed with cancer, and I'm going to go and take care of her. You must wait twelve hours before saying anything about what's happened to Beckett. If you snitch on me early, I will _know. _I have eyes and ears on the inside, and have bugged the Precinct, the morgue labs, Beckett's apartment and a dozen more places you can't even begin to think of. Slip up _once, _drop a hint, write a note, give any kind of clue, and Beckett will pay for what you do ten times over. Do you understand?"

"I understand," Castle grits out. These last few days have gone from bad to worse to terrible to a personalised kind of hell.

"Good. Now get in the car."

The doors of the Precinct lift ding open, and Mike and Castle are soon entering the bullpen, the latter of the two on autopilot, unable to really register anything.

"Dad!" A girl attached to a mass of red hair throws herself into Castle's arms.

"Hey, pumpkin. I'm fine. I'm fine. I'm okay."

(That's a lie. Beckett's gone. He's not okay. He'll never be okay.)

It only takes them a few minutes to "explain" things – that is, to tell everyone what Mike wants them to hear.

The story, as an intrigued Martha, Alexis, Lanie, Esposito, Ryan and Gates hear it is this:

- Beckett and Mike followed the footprint lead they found using his friend's Mass Spectrometer

- They found Castle in a basement in an old building in a shadier area of the Bronx

- There were no signs of his captors, but Beckett stayed behind to canvas the building

Castle watches Mike get congratulated for around five minutes, only just managing to keep from punching anything (preferably, Mike).

"Thanks, guys. I'm sorry I don't have any additional leads, but at least we've got Castle back, safe and sound, am I right? Anyway, there's something else I have to tell you all. I've quit my job as an ME. My mother has been diagnosed with terminal cancer, and I'm going to South Carolina to take care of her."

There's a universal noise of consolations and farewells; the only one who really knew Mike particularly well was Lanie, who gives him a hug. Castle wants to reach out and pull her away from him, but he can't.

He is absolutely powerless for the next twelve hours, because he can only imagine how Mike might make Beckett "pay". He knows her system is still swirling with incurably poison (incurable unless you're Mike), and his overactive writer's imagination is vividly projecting torture and assault onto his eyelids.

Though, from what's been happening so far, he thinks that perhaps his imagination is not overactive at all.

* * *

**Please review/comment/complain. I love every message and review I get.**

**3SF will be updated next, I've got a chapter for it half-done, so hang in there.**

**x. M**


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